xref: /openbmc/linux/drivers/cxl/cxl.h (revision a3cbcadf)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /* Copyright(c) 2020 Intel Corporation. */
3 
4 #ifndef __CXL_H__
5 #define __CXL_H__
6 
7 #include <linux/libnvdimm.h>
8 #include <linux/bitfield.h>
9 #include <linux/bitops.h>
10 #include <linux/io.h>
11 
12 /**
13  * DOC: cxl objects
14  *
15  * The CXL core objects like ports, decoders, and regions are shared
16  * between the subsystem drivers cxl_acpi, cxl_pci, and core drivers
17  * (port-driver, region-driver, nvdimm object-drivers... etc).
18  */
19 
20 /* CXL 2.0 8.2.5 CXL.cache and CXL.mem Registers*/
21 #define CXL_CM_OFFSET 0x1000
22 #define CXL_CM_CAP_HDR_OFFSET 0x0
23 #define   CXL_CM_CAP_HDR_ID_MASK GENMASK(15, 0)
24 #define     CM_CAP_HDR_CAP_ID 1
25 #define   CXL_CM_CAP_HDR_VERSION_MASK GENMASK(19, 16)
26 #define     CM_CAP_HDR_CAP_VERSION 1
27 #define   CXL_CM_CAP_HDR_CACHE_MEM_VERSION_MASK GENMASK(23, 20)
28 #define     CM_CAP_HDR_CACHE_MEM_VERSION 1
29 #define   CXL_CM_CAP_HDR_ARRAY_SIZE_MASK GENMASK(31, 24)
30 #define CXL_CM_CAP_PTR_MASK GENMASK(31, 20)
31 
32 #define   CXL_CM_CAP_CAP_ID_HDM 0x5
33 #define   CXL_CM_CAP_CAP_HDM_VERSION 1
34 
35 /* HDM decoders CXL 2.0 8.2.5.12 CXL HDM Decoder Capability Structure */
36 #define CXL_HDM_DECODER_CAP_OFFSET 0x0
37 #define   CXL_HDM_DECODER_COUNT_MASK GENMASK(3, 0)
38 #define   CXL_HDM_DECODER_TARGET_COUNT_MASK GENMASK(7, 4)
39 #define CXL_HDM_DECODER0_BASE_LOW_OFFSET 0x10
40 #define CXL_HDM_DECODER0_BASE_HIGH_OFFSET 0x14
41 #define CXL_HDM_DECODER0_SIZE_LOW_OFFSET 0x18
42 #define CXL_HDM_DECODER0_SIZE_HIGH_OFFSET 0x1c
43 #define CXL_HDM_DECODER0_CTRL_OFFSET 0x20
44 
45 static inline int cxl_hdm_decoder_count(u32 cap_hdr)
46 {
47 	int val = FIELD_GET(CXL_HDM_DECODER_COUNT_MASK, cap_hdr);
48 
49 	return val ? val * 2 : 1;
50 }
51 
52 /* CXL 2.0 8.2.8.1 Device Capabilities Array Register */
53 #define CXLDEV_CAP_ARRAY_OFFSET 0x0
54 #define   CXLDEV_CAP_ARRAY_CAP_ID 0
55 #define   CXLDEV_CAP_ARRAY_ID_MASK GENMASK_ULL(15, 0)
56 #define   CXLDEV_CAP_ARRAY_COUNT_MASK GENMASK_ULL(47, 32)
57 /* CXL 2.0 8.2.8.2 CXL Device Capability Header Register */
58 #define CXLDEV_CAP_HDR_CAP_ID_MASK GENMASK(15, 0)
59 /* CXL 2.0 8.2.8.2.1 CXL Device Capabilities */
60 #define CXLDEV_CAP_CAP_ID_DEVICE_STATUS 0x1
61 #define CXLDEV_CAP_CAP_ID_PRIMARY_MAILBOX 0x2
62 #define CXLDEV_CAP_CAP_ID_SECONDARY_MAILBOX 0x3
63 #define CXLDEV_CAP_CAP_ID_MEMDEV 0x4000
64 
65 /* CXL 2.0 8.2.8.4 Mailbox Registers */
66 #define CXLDEV_MBOX_CAPS_OFFSET 0x00
67 #define   CXLDEV_MBOX_CAP_PAYLOAD_SIZE_MASK GENMASK(4, 0)
68 #define CXLDEV_MBOX_CTRL_OFFSET 0x04
69 #define   CXLDEV_MBOX_CTRL_DOORBELL BIT(0)
70 #define CXLDEV_MBOX_CMD_OFFSET 0x08
71 #define   CXLDEV_MBOX_CMD_COMMAND_OPCODE_MASK GENMASK_ULL(15, 0)
72 #define   CXLDEV_MBOX_CMD_PAYLOAD_LENGTH_MASK GENMASK_ULL(36, 16)
73 #define CXLDEV_MBOX_STATUS_OFFSET 0x10
74 #define   CXLDEV_MBOX_STATUS_RET_CODE_MASK GENMASK_ULL(47, 32)
75 #define CXLDEV_MBOX_BG_CMD_STATUS_OFFSET 0x18
76 #define CXLDEV_MBOX_PAYLOAD_OFFSET 0x20
77 
78 #define CXL_COMPONENT_REGS() \
79 	void __iomem *hdm_decoder
80 
81 #define CXL_DEVICE_REGS() \
82 	void __iomem *status; \
83 	void __iomem *mbox; \
84 	void __iomem *memdev
85 
86 /* See note for 'struct cxl_regs' for the rationale of this organization */
87 /*
88  * CXL_COMPONENT_REGS - Common set of CXL Component register block base pointers
89  * @hdm_decoder: CXL 2.0 8.2.5.12 CXL HDM Decoder Capability Structure
90  */
91 struct cxl_component_regs {
92 	CXL_COMPONENT_REGS();
93 };
94 
95 /* See note for 'struct cxl_regs' for the rationale of this organization */
96 /*
97  * CXL_DEVICE_REGS - Common set of CXL Device register block base pointers
98  * @status: CXL 2.0 8.2.8.3 Device Status Registers
99  * @mbox: CXL 2.0 8.2.8.4 Mailbox Registers
100  * @memdev: CXL 2.0 8.2.8.5 Memory Device Registers
101  */
102 struct cxl_device_regs {
103 	CXL_DEVICE_REGS();
104 };
105 
106 /*
107  * Note, the anonymous union organization allows for per
108  * register-block-type helper routines, without requiring block-type
109  * agnostic code to include the prefix.
110  */
111 struct cxl_regs {
112 	union {
113 		struct {
114 			CXL_COMPONENT_REGS();
115 		};
116 		struct cxl_component_regs component;
117 	};
118 	union {
119 		struct {
120 			CXL_DEVICE_REGS();
121 		};
122 		struct cxl_device_regs device_regs;
123 	};
124 };
125 
126 struct cxl_reg_map {
127 	bool valid;
128 	unsigned long offset;
129 	unsigned long size;
130 };
131 
132 struct cxl_component_reg_map {
133 	struct cxl_reg_map hdm_decoder;
134 };
135 
136 struct cxl_device_reg_map {
137 	struct cxl_reg_map status;
138 	struct cxl_reg_map mbox;
139 	struct cxl_reg_map memdev;
140 };
141 
142 struct cxl_register_map {
143 	struct list_head list;
144 	u64 block_offset;
145 	u8 reg_type;
146 	u8 barno;
147 	union {
148 		struct cxl_component_reg_map component_map;
149 		struct cxl_device_reg_map device_map;
150 	};
151 };
152 
153 void cxl_probe_component_regs(struct device *dev, void __iomem *base,
154 			      struct cxl_component_reg_map *map);
155 void cxl_probe_device_regs(struct device *dev, void __iomem *base,
156 			   struct cxl_device_reg_map *map);
157 int cxl_map_component_regs(struct pci_dev *pdev,
158 			   struct cxl_component_regs *regs,
159 			   struct cxl_register_map *map);
160 int cxl_map_device_regs(struct pci_dev *pdev,
161 			struct cxl_device_regs *regs,
162 			struct cxl_register_map *map);
163 
164 #define CXL_RESOURCE_NONE ((resource_size_t) -1)
165 #define CXL_TARGET_STRLEN 20
166 
167 /*
168  * cxl_decoder flags that define the type of memory / devices this
169  * decoder supports as well as configuration lock status See "CXL 2.0
170  * 8.2.5.12.7 CXL HDM Decoder 0 Control Register" for details.
171  */
172 #define CXL_DECODER_F_RAM   BIT(0)
173 #define CXL_DECODER_F_PMEM  BIT(1)
174 #define CXL_DECODER_F_TYPE2 BIT(2)
175 #define CXL_DECODER_F_TYPE3 BIT(3)
176 #define CXL_DECODER_F_LOCK  BIT(4)
177 #define CXL_DECODER_F_MASK  GENMASK(4, 0)
178 
179 enum cxl_decoder_type {
180        CXL_DECODER_ACCELERATOR = 2,
181        CXL_DECODER_EXPANDER = 3,
182 };
183 
184 /**
185  * struct cxl_decoder - CXL address range decode configuration
186  * @dev: this decoder's device
187  * @id: kernel device name id
188  * @range: address range considered by this decoder
189  * @interleave_ways: number of cxl_dports in this decode
190  * @interleave_granularity: data stride per dport
191  * @target_type: accelerator vs expander (type2 vs type3) selector
192  * @flags: memory type capabilities and locking
193  * @target: active ordered target list in current decoder configuration
194  */
195 struct cxl_decoder {
196 	struct device dev;
197 	int id;
198 	struct range range;
199 	int interleave_ways;
200 	int interleave_granularity;
201 	enum cxl_decoder_type target_type;
202 	unsigned long flags;
203 	struct cxl_dport *target[];
204 };
205 
206 
207 enum cxl_nvdimm_brige_state {
208 	CXL_NVB_NEW,
209 	CXL_NVB_DEAD,
210 	CXL_NVB_ONLINE,
211 	CXL_NVB_OFFLINE,
212 };
213 
214 struct cxl_nvdimm_bridge {
215 	struct device dev;
216 	struct cxl_port *port;
217 	struct nvdimm_bus *nvdimm_bus;
218 	struct nvdimm_bus_descriptor nd_desc;
219 	struct work_struct state_work;
220 	enum cxl_nvdimm_brige_state state;
221 };
222 
223 struct cxl_nvdimm {
224 	struct device dev;
225 	struct cxl_memdev *cxlmd;
226 	struct nvdimm *nvdimm;
227 };
228 
229 /**
230  * struct cxl_port - logical collection of upstream port devices and
231  *		     downstream port devices to construct a CXL memory
232  *		     decode hierarchy.
233  * @dev: this port's device
234  * @uport: PCI or platform device implementing the upstream port capability
235  * @id: id for port device-name
236  * @dports: cxl_dport instances referenced by decoders
237  * @decoder_ida: allocator for decoder ids
238  * @component_reg_phys: component register capability base address (optional)
239  */
240 struct cxl_port {
241 	struct device dev;
242 	struct device *uport;
243 	int id;
244 	struct list_head dports;
245 	struct ida decoder_ida;
246 	resource_size_t component_reg_phys;
247 };
248 
249 /**
250  * struct cxl_dport - CXL downstream port
251  * @dport: PCI bridge or firmware device representing the downstream link
252  * @port_id: unique hardware identifier for dport in decoder target list
253  * @component_reg_phys: downstream port component registers
254  * @port: reference to cxl_port that contains this downstream port
255  * @list: node for a cxl_port's list of cxl_dport instances
256  */
257 struct cxl_dport {
258 	struct device *dport;
259 	int port_id;
260 	resource_size_t component_reg_phys;
261 	struct cxl_port *port;
262 	struct list_head list;
263 };
264 
265 struct cxl_port *to_cxl_port(struct device *dev);
266 struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport,
267 				   resource_size_t component_reg_phys,
268 				   struct cxl_port *parent_port);
269 
270 int cxl_add_dport(struct cxl_port *port, struct device *dport, int port_id,
271 		  resource_size_t component_reg_phys);
272 
273 struct cxl_decoder *to_cxl_decoder(struct device *dev);
274 bool is_root_decoder(struct device *dev);
275 struct cxl_decoder *
276 devm_cxl_add_decoder(struct device *host, struct cxl_port *port, int nr_targets,
277 		     resource_size_t base, resource_size_t len,
278 		     int interleave_ways, int interleave_granularity,
279 		     enum cxl_decoder_type type, unsigned long flags);
280 
281 /*
282  * Per the CXL specification (8.2.5.12 CXL HDM Decoder Capability Structure)
283  * single ported host-bridges need not publish a decoder capability when a
284  * passthrough decode can be assumed, i.e. all transactions that the uport sees
285  * are claimed and passed to the single dport. Default the range a 0-base
286  * 0-length until the first CXL region is activated.
287  */
288 static inline struct cxl_decoder *
289 devm_cxl_add_passthrough_decoder(struct device *host, struct cxl_port *port)
290 {
291 	return devm_cxl_add_decoder(host, port, 1, 0, 0, 1, PAGE_SIZE,
292 				    CXL_DECODER_EXPANDER, 0);
293 }
294 
295 extern struct bus_type cxl_bus_type;
296 
297 struct cxl_driver {
298 	const char *name;
299 	int (*probe)(struct device *dev);
300 	void (*remove)(struct device *dev);
301 	struct device_driver drv;
302 	int id;
303 };
304 
305 static inline struct cxl_driver *to_cxl_drv(struct device_driver *drv)
306 {
307 	return container_of(drv, struct cxl_driver, drv);
308 }
309 
310 int __cxl_driver_register(struct cxl_driver *cxl_drv, struct module *owner,
311 			  const char *modname);
312 #define cxl_driver_register(x) __cxl_driver_register(x, THIS_MODULE, KBUILD_MODNAME)
313 void cxl_driver_unregister(struct cxl_driver *cxl_drv);
314 
315 #define CXL_DEVICE_NVDIMM_BRIDGE	1
316 #define CXL_DEVICE_NVDIMM		2
317 
318 #define MODULE_ALIAS_CXL(type) MODULE_ALIAS("cxl:t" __stringify(type) "*")
319 #define CXL_MODALIAS_FMT "cxl:t%d"
320 
321 struct cxl_nvdimm_bridge *to_cxl_nvdimm_bridge(struct device *dev);
322 struct cxl_nvdimm_bridge *devm_cxl_add_nvdimm_bridge(struct device *host,
323 						     struct cxl_port *port);
324 struct cxl_nvdimm *to_cxl_nvdimm(struct device *dev);
325 bool is_cxl_nvdimm(struct device *dev);
326 int devm_cxl_add_nvdimm(struct device *host, struct cxl_memdev *cxlmd);
327 #endif /* __CXL_H__ */
328